Ionized-chamber device



CED. BABCOCK.

IONIZED CHAMBER DEVICE.

APPLICATION mzo OCT. n, 1916. RENEWED MAY 23.1919.

1,341,006. Patented M y 25,1920.

IN VEN TOR.

ATTORNEY UNITED STATES PATENT OFFICE.

cmronn DUDLEY BAIBCOCK, or miwronx, N. 1., ASSIGNOB or ONE-HALF 'ro .romw

. nmson, or new roux, n. Y.

iomznn cmmnnn nnvrcn.

Patented May 25, 1920.

Application fledpetober 11, 1918, Serial No. 124,989. Renewed Kay 23, 1819. Serial No. 289,378.

To all whom itma concern:

Be it known t at I, CLIFFORD DUDLEY BABGOOK, a citizen of the United States, and resident of New York, borough of Manhattan, in the county and State of New York, have invented certain new'and useful Improvements in Ionized-Chamber Devices, of which .the following is a specification.

This invention relates to certain improvements in ionized chamber devices of that general type in which an electric current is caused to .pass through a field of ionic activity within a sealed chamber or envelop. Devices of this general character are employed as generators, receivers, or indicators and converters of high frequency electric currents and for various other purposes. Various types of these devices are known in the market, such for instance as the Audion, Kenotron, Plyotron and Oscillion, etc, and in which the operating elements are sealed in a more or less perfectly evacuated vessel and include one hot and two or more cold elements.

In the construction of some of these, the usual practice is to mount the metal parts on two glass members independent of each other, seal one of these glass members in the bulb or other envelop, and then insert the other glass member, with the elements supported by it, within the envelop. While the glass at the sealing point is still hot and plastic, the members are brought as near to the desired relationship as it is pos sible for the operator to, by gaging the distance between theelements and their relative positions solely by their appearance when viewed through the wall of the envelop and by his memory of the appearance of the devices previously assembled. I-hus, any accurate determination of the distances and relative positions is practically im possible.

Even though the metal operating elements be mounted on a single glass support before being inserted and sealed within the envelop, it often happens during handling or shipment that, small glass connecting and supporting rods, bars, or braces within the envelop are broken or that the elements are displaced or bent from the initial position. It is then practically impossible to restore them to their original condition or relative positions. One of the main objects of my invention isto so design the operating ele- A desirable that the ments and so rigidly secure-them in the predetermlned relative positions, that the greatest accuracy may be secured in gaging the distances between the parts before they are sealed in and no special skill is required in inserting the parts within the envelop and sealin them in.

In evices of this character, the uniformity of operation depends very largely upon the spacing of the elements among themselves. After suitable distances have once been determined by experiment, it is highly manufacturer be able to duplicate the product with great accuracy and with a permissible limit of variation as small as one one-thousandth of an inch.

By meansof my invention, such accuracy is easily and practically possible and I am able to produce in large quantities a uniform product which will stand comparatively rough usage including shaking and jarring without varying the relative positions of the parts and without changing the initial adjus'tment. The parts may be very easily and very accuratelyadjusted with relation to each other by the bending of the metal supports or in other ways after they have been sealed in the glass support and before being inserted within the envelop, and therefore, there is nothing left to the guess-work or judgment or the glass-blowers eye.

I am aware that devices of this general character have been designed in which the elements have been arranged uni-axial and therefore I do not claim that arrangement broadly as my invention, but as an important feature of my improved construction I employ this uni-axial arrangement with the output electrode in the form of a tube or sleeve encircling a skeleton input electrode and the latter encircling the hot cathode. This enables me to secure the maximum operating surface and permits the utilization of'the entire ionized space about the entire circumference of. the hot cathode.

The degree of exhaustion of the chamber or the character of gaseous medium therein, as well as the particular arrangement of the device in circuit,-or the use to which it is put, forms no portion of my present invention. My invention relates primarily to the construction and relative arrangement of the operating. elements within the chamber..

In the accompanying drawings, I have illustrated merely one embodiment of my invention which is partimilarly adapted for use as an amplifier, oscillator, relay or detector of alternating or interrupted currents in a wireless signaling system, but I do not desire to be limited to this specific constructionnor any particular use.

Figure 1 is a central longitudinal section through the glass stem and operating ele ments carried thereby, prior to insertion within the envelop;

Fig. 2 is a perspective view of an envelop within which the device shown in Fig. 1 may be inserted; v

Fig. 3 is a central longitudinal section of the complete device; and

Fig. 1 is a transverse section on the line 44 of Fig. 3.

The glass element which serves as a support for the operating elements may be formed of a hollow stem substantially as shown in Fig. 1. The stem includes a supporting part 10, an enlarged or bulb-like body portion 11 and a tail 12 serving as a handle and is a means for sealing the joint to the shell. The stem support 10 is formed by melting and closing together the upper end of the stem which then assumes the form of a transversely extending ridge or lip. Supported by this stem are the three operating elements of the device, namely a filament or hot cathode 15, an output electrode or plate in the form of a metal cylinder 14 and an input electrode or grid in the formiof a helical coil 13. The filament extends in the direction of the axis of the stem and its opposite ends are connected to two supports 16 and 17, each in-the form of comparatively heavy wire sealed in the glass support 10 and connected to the leads 18 and 19 which extend through the hollow stem.

The filament support 16 is. eccentrically disposed and extends lengthwise of the device and has its terminal bent laterally into the axis ofthe device. Both of the filament supports may be readily bent during assembling and after being sealed in the support so that the filament may be held taut or straight and its position adjusted to bring it into line with the axis of the parts here- I inafter described.

The output electrode or plate is in the form of a tube of metal, or other conducting material, or sleeve encircling the filament and preferably of cylindrical form and concentric with said filament. As shown, the glass stem has a cylindrical portion between the bulb 11 and terminal lip and on this, one end of the tube, sleeve or cylinder 14 may telescope with a tight friction fit so as to be rigidly supported by said stem. It is of course evident that other means might be employed for rigidly securing the two parts together. In practice, the sleeve may be slitt-ed at its lower end so as to permit of a slight contraction or expansion of the sleeve in accordance with slightly varying sizes of glass stems and if desired, a wire 20, or any other form of clamp may be wrapped around the base of the cylinder to hold it in contracted and snugly fitting position.

The input electrode or grid is in skeleton form within the sleeve 1-4 and encircles the filament. It may be constructed of an annular row of parallel wires or of wire netting or other reticulated conducting material, but it is preferably a helical coil. To get the desired uniform utilization of the ionized field around the hot cathode filament, the filament plate and grid are coaxial. The grid hasone end anchored in the glass stem 10 and its'opposite end has a lead extending out through the opposite open end of the sleeve. In assembling these three metal operating parts, the filament supports and the grid are first sealed in the glass stem and after sealing, may be easily adjusted to coaxial positions with the greatest accuracy. Thesleeve or tube may then be slipped on and, if necessary, clamped in position.

It is essential that the spiral element shall not touch the filament and thereby cause the latter to burn out, and shall not touch both the filament and the cylinder to thereby burn out the telephone. Supporting and connecting parts may be employed to prevent such alteration in the position of the spiral element and at the same time hold the parts in such relative positions that the action takes place substantially .uniformly on all sides of the axis of the filament.

To accomplish this result, glass beads may be fused to certain of the arts adjacent the upper end of the sleeve. The upper end of the spiral element constitutes, or is connected to, a lead 21 while a second lead 22 is secured directly to the wall of the sleeve. A glass bead 23 may be fused around these two leads closely adjacent the end of the sleeve and a second glass bead 2-l may be fused about the filament support 16 and the upper end of the spiral element lead. These heads will effectively prevent any alteration in the position of the parts after they are once assembled and while the stem and its supporting parts. are being sealed in the envelop as hereinafter described. Either or both of these two beads may be omitted if the sealer-in is sufiiciently careful when inclosing the elements within the envelop. The envelop, by its engagements with the leads 21 and 22, may be sufficient to hold the parts steady without the beads.

The support 16 is illustrated as extending upwardly within the sleeve and between the side thereof and the spiral element. If desired, this support might extend up outside of the sleeve but if it be inside, it is desirable to provide it with an insulation which may be in the form of a small glass tube This insulation prevents the loss which would result from the tendenc of the Edison efi'ect to spend itself direct y on the supporting member and thereby reduce the efliciency of the device by a proportionate amount.

The filament is illustrated as including a single, straight length. If desired, it may be in the form of a coil concentric with the spiral element 15 and thereby the radiating surface may be increased and a means provided for adjusting the filament resistance. In order that all of the arts may be uniaxial, I preferably provi e but one filament or hot cathode although a second closely adj acent thereto may be provided as a reserve, if desired.

After the assembly of the parts and the adjustment andvinter-relationship has been established as shown in Fig. 1, I inclose the operating elements and a portion of the stem within a suitable envelop. This may be in the form of an approximately spherical bulb, a cylindrical sleeve, or of any other desired shape whatsoever and may be of.

any desired and suitable material. v In Fig. 2, I have shown an envelop in the form of a thin glass cylinder 26 having a small neck 27 at one end and being open and of ap- ,proximately the diameter of the enlarged portion 11 of the stem at the other end.

The device as shown in Fig. 1 is inserted into the envelop with the lead wires 21 and 22 projecting through the neck 27 and with the open lower end of the envelop adjacent to or fitting the enlarged portion 11 of the same.- The operator then melts the neck 27 and pinches it together to eiiectively seal in the leads 21. and 22 and, by properly heating and manipulating the stem and the lower end of the envelop, is able to connect the parts together and form a single, integral, air-tight structure, substantially as shown in Fig. 3. The lower end or tail 12 of the stem, which has served as a handle, may be cut 01? to the required length and, if desired,

connected to any suitable form of base. Merely as an example of such a base, I have shown a screw-threaded base 28. The envelop may be tubulated at any desired-point, as for instance at 29, and the air exhausted to any desired degree or replaced by any other gas or gases.

aving thus described my invention;

what I claim as new and desire to secure by Letters Patent is: E

1. A device of the class described including a stem, a sleeve encircling a portion of said stem and supported thereby, a hot cathode within said sleeve and extending lengthwise thereof, a pair of supports carried by said stem within said sleeve and con nected to opposite ends of said cathode, said supports being laterally adjustable to bring the cathode into the axis of the sleeve, an

electrode encircling said cathode within said sleeve, and also supported b said stem, in-

sulating connections for ho ding said electrode, sleeve and cathode substantially rigid inrespect to each other at the end of the sleeve opposite to said stem, and an envelop inclosing said parts and sealed to said stem.

2. A device of the class described, including a stem, a sleeve encircling a portion of said stem and supported thereby, a hot cathode within said sleeve and extending lengthwise thereof, a pair of supports carried by said stem within said sleeve and extending lengthwise thereof, and connected to opposite ends of said cathode, said supports being laterally adjustable to bring the cathode into the axis of the sleeve, an electrode encircling said cathode within said sleeve and also supported by said stem, insulating connections for holding said elec trode and sleeve substantially rigid in retending lengthwise thereof, and connected to opposite ends of said cathode, said supports being laterally adjustable to bring the cathode into the axis of the sleeve, an electrode encircling said cathode within said sleeve and also supported by said stem, insulating connections for holding said electrode and cathode substantially rigid in respect to each" other at the end ofthe sleeve opposite to said stem, and an envelop encircling said parts and sealed to said stem.

4. A device of the class described, including a glass stein, an output electrode supported thereby, an input electrode supported by said stem, a hot cathode, supports carried by said stem and connected to said cathode adjacent to the opposite ends of said electrodes and insulation separate from said stem and encircling one of said supports.

5. A device of'the class described, including a glass stem, an output electrode supcathode adjacent to the opposite ends of said electrodes, and a glass sleeve separate from said stem and encircling one of said supports.

6. A three element ionized chamber device for detection or generation of oscilla.

tory currents,'including a chamber, a glass presenting a cylindri -al V: I1, a second electrode in the form of a helical coil mounted co-axially within said first mentioned electrode, a support therefor sealed in the stem, a third electrode in the form of a. heater within said helical coil, and a pair of current conducting supports for said heater carried by said stem and terminating at said contacts, said electrodes and heater being ad justable to proper positions relative to each other on said stem before insertion and sealin within said chamber.

4. A device of the class described, including a glass stein, an outer cylindrical wall electrode, an intermediate helical coil electrode co-axial therewith and disposed therein, a filament within said coil, said elec trodes and-filament being supported by said stem and adjustable on thelatter in respect to each other, and an envelop inclosing said electrodes and filament and sealed to said stem, a portion of said stem projecting to the exterior of said chamber to serve as a support for said device. a

8. A device of the class described, including a stem, a base encircling the outer end hot cathode within said sleeve and extending lengthwise thereof, a pair of supports carried by said stem and connected to opposite ends of said cathode, an electrode encircling" said cathode within said sleeve and supported by said stem, and an envelop inclosing said parts and sealed to said stem.

9. A device of the class described, includinga glass stein, a cylindrical output electrode supported thereby, a hot cathode within said electrodeand extending lengthwise thereof, a pair of supports carried by said stem and connected to opposite ends of said cathode, a helical coil electrode encircling said. cathode within said cylindrical electrode and also supported by said stem, and an envelop encircling said parts and sealed to said stem.

Signed at New York city, in the county of New York and State of New York, this 10th day of October, A. D. 1916.

CLIFFORD DUDLEY BABCOGK. 

